Rotating disk storage device with cooling air flow control

ABSTRACT

A storage device includes a partition wall dividing an interior of a casing into a disk chamber and a drive chamber. Recording disks are rotatably disposed in the disk chamber. Arms, each supporting a read/write head at a distal end portion thereof, are capable of extending into the respective spaces between the recording disks through an opening of the partition wall. An actuator is mounted within the drive chamber for linearly reciprocating the arms to cause the heads to skim across recording surfaces of the recording disks. An interrupting surface is formed on a portion of the partition wall at a downstream side of the arm with respect to an air flow due to the rotation of the recording disks, for interrupting the air flow to convert a dynamic pressure of the air flow into a static pressure thereof. With this arrangement, the air is prevented from flowing back from the drive chamber into the disk chamber.

FIELD OF THE INVENTION AND RELATED ART STATEMENT

This invention relates to a data storage disk device such, for example,as a magnetic disk device.

In a data storage disk device such as a magnetic disk device, there isused a flying head slider which flies or skims over a disk surface witha gap of 0.1 μm-0.2 μm therein between, and is supported by an airbearing. Therefore, in order to ensure sufficient reliability of thedevice, it is necessary to provide a very clean environment in thedevice.

In a magnetic disk device provided with a linear actuator for driving anarm carrying a head slider, complicated drive mechanisms, such as aguide portion and a bearing portion for the actuator, are exposed withinthe device, and therefore it is necessary to provide means for dealingwith dust accidentally produced from such drive mechanism. Also, inorder to prevent an off-track driving of the arm due to thermaldeformation of component parts within the device, it is necessary tocirculate the air in the device so as to cool heat-generating parts suchas an actuator.

Japanese Patent Unexamined Publication No. 61-196494 and U.S. Pat. Nos.4,780,776 and 5,031,059 disclose a construction in which a casing isdivided by a partition wall into a disk housing portion for receivingdisks therein, and a drive mechanism portion receiving an actuatortherein. According to this reference, the disk housing portion isisolated from the drive mechanism portion, and therefore the disks areprotected against accidental contamination from the drive mechanismportion. A through opening through which an arm passes is formed in thepartition wall, and an air stream flows from the disk housing portion tothe drive mechanism portion through the through opening to coolcomponent parts within the device.

In such a device, it is important that the air, once passed the throughopening, should be prevented from flowing back from the drive mechanismportion into the disk housing portion. By doing so, efficient air flowcirculation is produced, and the disk housing portion is kept veryclean.

Therefore, in these techniques, in order to prevent the reverse air flowthrough the through opening, it has been proposed to provide apressure-increasing means in the disk housing portion, with the meansextending radially inwardly between the disks to increase the pressurewithin the disk housing portion, so as to strengthen the air streamflowing between the disks in a radially outward direction from thecenter portion of the disks.

The reverse air flow through the through opening is classified mainlyinto following three kinds:

(1) A reverse air flow at a downstream side of the arm;

(2) A reverse air flow between each of opposite end disks (in a verticaldirection between a stack of disks) and a disk housing wall; and

(3) A reverse air flow due to the mixing of streams at an upstream sideof the arm.

When the arm is inserted inward deeply into the space between the disks,the pressure in this space at the downstream side of the arm decreases,so that the reverse air flow (1) is produced. One proposal to preventthe reverse air flow (1) is to provide spoilers at the downstream sideof the arm to sufficiently increase the pressure to compensate for thepressure decrease at the downstream side of the arm.

However, in order to completely prevent the reverse air flow (1) withsuch a method, spoilers sufficiently larger in size than the arm areneeded, as shown in FIGS. 1 and 2 of Japanese Patent UnexaminedPublication No. 61-196494. Therefore, in this case, increased powerconsumption due to an air flow loss caused by the spoilers presentsanother serious problem.

Furthermore, in a stagnation region at the downstream side of the arm,there is created a pressure gradient in which the pressure is higher atthe outer peripheral portion of the disk than at the inner peripheralportion because of differences of the peripheral speed in the radialdirection of the disk. Therefore, if the spoiler, provided between thedisks at the downstream side of the arm, is not of a sufficient size,the air is drawn from the outside of the disks into the space betweenthe disks at the downstream side of the arm. Because of this suctionphenomenon, there is encountered a problem that the air which may havebeen contaminated is drawn from the outside of the disk housing portionto the vicinity of the head slider.

The reverse air flow (2) is attributable to the fact that the energy ofthe air stream in the flow passage between each of the opposite enddisks and the disk housing wall is extremely smaller than the energy ofthe air stream between the disks. In order to prevent such a reverse airflow, it is effective to sufficiently increase the pressure at theopposite end portions of the disk housing wall in the direction of theaxis thereof. Therefore, in the construction disclosed in JapanesePatent Unexamined Publication No. 63-239666, a spoiler is providedbetween each of the opposite end disks and the disk housing wall.

With such a construction, however, if the interval between each of theopposite end disks and the disk housing wall is so small that thespoiler cannot be easily installed, the manufacturing cost is increased.

As shown in FIG. 4 of Japanese Patent Unexamined Publication No.63-239666, the reverse air flow (3) is a reverse air flow of dust whichis produced through a plane of mixing of air streams developing at thatportion of the through opening disposed upstream of the arm, when thearm is hardly inserted into the space between the disks. In order toprevent such a reverse flow, it is necessary to provide means fordirecting the stream mixing plane toward the drive mechanism portion.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a rotary disk-typestorage device in which the above-mentioned reverse air flows (1) to (3)are prevented without increasing an air flow loss, component partswithin the device can be cooled quite efficiently, the interior of adisk housing has a contaminant-free environment, and a high level ofreliability of the device is achieved.

According to the present invention, there is provided a storage devicecomprising: a casing; a partition wall dividing an interior of thecasing into a disk chamber and a drive chamber; a recording diskdisposed in the disk chamber; means for rotating the recording disk; anarm supporting a read/write head, the arm being adapted to extendthrough the partition wall; means disposed in the drive chamber forlinearly moving the arm to cause the head to skim over a recordingsurface of the recording disk in a radial direction; and means disposedat a downstream side of the arm with respect to an air flow due to therotation of the recording disk, for interrupting the air flow to converta dynamic pressure of the air flow into a static pressure thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a magnetic disk device provided inaccordance with one embodiment of the present invention;

FIG. 2 is a perspective view showing a through opening provided in thedevice of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line III--III of FIG.1;

FIG. 4 is a view illustrating air flows near an arm in the device ofFIG. 1;

FIG. 5 is a view illustrating air flows near an arm in a conventionaldevice;

FIGS. 6 to 11 are fragmentary, cross-sectional views showing modifiedflow interrupting means, respectively;

FIGS. 12A to 12E are cross-sectional views taken along the lines ofXII--XII of FIG. 10, showing modified forms of the invention in whichspoilers are provided upstream of an arm;

FIG. 13 is a cross-sectional view of a modified flow interrupting means;and

FIGS. 14 to 16 are cross-sectional views of further modified magneticdisk devices according to respective embodiments of the presentinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A preferred embodiment of a magnetic disk device of the presentinvention comprises disks 1, as shown in FIG. 1. The disks 1 arerotatable in a direction of arrow A in FIG. 1. A flying head 51 forwriting and reading data relative to the disk 1 is provided on a distalend of each arm 5. In this magnetic disk device, a casing 3 of a sealedconstruction is divided by a partition wall 2 into a disk housingportion (disk chamber) 4 and a drive mechanism portion (drive chamber).The disks 1 are received within the disk housing portion 4 whereas anactuator 10 for driving the arms 5 is housed in the drive mechanismportion. The partition wall 2 has a through opening 6 through which thelinearly-movable arms 5 extend, and also has an opening 9 in which afilter 8 is provided. The partition wall 2 has a surface 7 which isdisposed adjacent to the downstream side of the arm 5, and serves tointerrupt an air stream in a direction of the circumference of thedisk 1. The magnetic disk device is used in a vertically-disposedcondition, that is, in such a position that a direction of the gravityis on a plane of rotation of the disk 1, and is perpendicular with adirection of the movement of the arm 5.

A portion of the partition wall 2 disposed at the upstream side of thearm 5 is spread or diffused outwardly so that the air flow or streambetween the disks 1 can be smoothly directed toward the interruptingsurface 7. As shown in FIG. 2, the partition wall 2 is spread ordiffused toward the actuator 10 at its opposite axial end portions 22(in the direction of stack of the disks 1) in a slightly larger amountthan at a portion of the partition wall 2 intervening between theopposite axial end portions 22.

The interrupting surface 7 extends over the entire length of the throughopening 6 in the direction of stack of the disks 1, as shown in FIG. 3.Also, the interrupting surface 7 extends radially outwardly across atangential plane (indicated by a two dot chain line) of the partitionwall 2 passing through the upstream-side end of the through opening 6,and extends generally parallel to the arm 5, as shown in FIG. 4. Adistance d₂ between the interrupting surface 7 and the arm 5 is slightlysmaller than a distance d₁ between the above tangential plane and anopen end 21 of the partition wall 2. Here, the term "tangential plane"means a tangential plane substantially defining the direction of flow ofair due to the rotation of the disks, and does not mean a tangentialplane as used for a chamfered surface.

Incidentally, in order to facilitate an integral casting of the casing3, a draft of about 5° with respect to the arm 5 is provided on theinterrupting surface 7, as shown in FIG. 4, and then the interruptingsurface 7 is not exactly parallel to the arm 5. Whether or not the draftof such a degree is provided is not significant.

Next, the operation of the above construction will now be described.

When the disks 1 rotate in the direction of arrow A, an air stream isproduced in the disk housing portion 4 and flows into the drivemechanism portion via the through opening 6. The air stream thus flowedinto the drive mechanism portion cools heat-generating parts of theactuator 10, and then is filtered by the filter 8, and is returned tothe disk housing portion 4 via the opening 9. Thus, the air circulatesthrough the casing 3.

Here, the air stream in the disk housing portion 4 is restricted in itsflow direction so as to flow along the partition wall 2, and flows alonga flow passage defined by the tangential plane and a plane (indicated bya one dot chain line in FIG. 4) passing through the open end 21 of thepartition wall 2 and parallel to the tangential plane. Then, this airstream is interrupted by the interrupting surface 7 to change itsdirection as indicated by arrow C, and at the same time dynamic pressureof this air stream is converted into a static pressure to form ahigh-pressure area 17, and this air stream flows into the drivemechanism portion through the through opening 6. The pressure gradientat downstream side of the arm 5 from the drive mechanism portion towardthe disk housing portion 4, is locally interrupted by the high-pressurearea (pressure peak) 17, thereby preventing the air from flowing backfrom the drive mechanism portion to the disk housing portion 4.

In this embodiment, the opposite end portions 22 of the partition wall 2are further spread as shown in FIG. 2, so that the flow of the air fromthe disk housing portion 4 to the drive mechanism portion is promoted atthese end portions 22. With this construction, the reverse flow producedat the opposite end disks as described in Japanese Patent UnexaminedPublication No. 63-239666 is prevented. However, even if the oppositeend portions 22 are not further spread, the reverse air flow downstreamof the arm, which gives the largest influence, is prevented.

On the other hand, without the interrupting surface 7 as is the casewith the construction disclosed in U.S. Pat. No. 4,780,776, a reverseair flow B₁ drawn from the drive mechanism portion, due to a pressuredrop downstream of the arm 5, as well as a reverse air flow B₂ drawnalong the arm 5 would be formed as shown in FIG. 5. The reverse flow B₂is produced by a pressure gradient in a stagnation area 13 along the arm5, which is caused by a difference of the peripheral speeds in theradial direction of each disk. Both of the reverse flows B₁ and B₂ are,of course, harmful, and besides there is encountered a disadvantage thatthe reverse flow B₂ carries dust from the drive mechanism portion as faras a position near the head slider 51.

FIG. 6 shows a modified embodiment in which an interrupting surface 7has a curved configuration. In this case, an outflow end portion of theinterrupting surface 7 is made generally parallel to the arm 5 so thatan outflow C of air from the space between the disks 1 can flow alongthe arm 5.

FIG. 7 shows another modified embodiment in which a separateinterrupting member 71 is combined with a partition wall 2. In thiscase, the interrupting member 71 of a suitable design can be selected inaccordance with various conditions.

When a sufficient length of an interrupting surface 7 in a radialdirection of the disk cannot be obtained, a part of an actuator mountingmeans 11 can be used as a part of the interrupting surface, so that theinterrupting surface can be substantially extended, as shown in FIG. 8.

In further modified embodiments in FIGS. 9 and 10, respectively, aportion or an area of a through opening 6 disposed on an upstream sideof the arm 5 is larger for assembly purposes. In this case, even if thatportion of a partition wall 2 disposed at the upstream side of thethrough opening 6 is hardly spread or diffused outwardly, an air streamor flow can be directed toward an interrupting surface 7, and a reverseair flow from the downstream side of the arm 5 is prevented. In thiscase, the problem is a reverse flow due to the mixing of streams M atthe portion of the through opening 6 disposed at the upstream side ofthe arm 5, as shown in FIG. 9. However, with the type of disk device inwhich the arms 5 are always inserted into the disk housing portion 4 asshown in FIG. 9, the pressure within the disk housing portion 4 isincreased by the arms 5, and at the upstream side of the arm 5, thestream mixing plane is shifted toward the drive mechanism portion,thereby preventing the reverse flow. When spoilers 23 are extendedradially inwardly from a partition wall 2 as shown in FIG. 10, theyincrease the pressure within the disk housing portion 4, so that thestream mixing plane is more positively shifted toward the drivemechanism portion, and the overall reverse air flow is effectivelyprevented. In this case, the purpose of the spoiler 23 is not to fullyincrease the pressure downstream of the arm 5, but to shift the streammixing plane toward the drive mechanism portion, and then it has beenconfirmed through experiments that a sufficient amount of insertion ofthe spoiler 23 into the space between the disks is about one-tenth ofthe radius of the disk. Incidentally, as shown in FIG. 11, if a separatemember of an L-shaped cross-section is mounted on a partition wall 2 toserve as a spoiler 23 and as an interrupting surface 7, the samefunction as the above can be obtained by an easy assembly operation.

Usually, the spoilers 23 have the same configuration, as shown in FIGS.12A and 12B. However, particularly when the spaces between the end disk1 and a casing 3 are large, and a reverse air flow at these portions mayoccur, spoilers 23' longer than the other spoilers 23 are provided inthe respective spaces between the end disk 1 and the casing 3, as shownin FIGS. 12C, 12D and 12E.

With respect to the arrangement shown in FIG. 12E, in order to deal withthe temperature rise between the disks due to air flow loss, the centralspoilers 23" are also made longer.

In a further modified embodiment shown in FIG. 13, no spoiler isprovided, and a partition wall is not spread radially outwardly.However, when each arm 5 is always disposed between disks 1 as in a diskdevice in which only an inner peripheral portion of the disk is used asa recording surface, the arm 5 itself shifts a high velocity air streamflowing along the outer periphery of the disk 1 toward a drive mechanismportion. Therefore, with the construction shown in FIG. 13, satisfactoryeffects can be achieved.

In a further modified embodiment shown in FIG. 14, a relatively flatpartition wall 2 is used. In this case, a portion 20 of the partitionwall 2 at an upstream side of a through opening 6 is slightly bent sothat an air stream can be directed toward an interrupting surface 7. Inthis case, the partition wall 2 is of a simple construction, andtherefore if the partition wall 2 is separate from a casing 3, themanufacturing cost is reduced.

In view of the nature of the present invention, the disks 1 arepreferably isolated by the partition wall 2 as described for the aboveembodiments, but, even where the disks 1 are not isolated from anactuator 10 as shown in FIGS. 15 and 16, such a construction is stillsufficiently effective with respect to the cooling of the actuator 10.In this case, particularly when an air stream guide 22 is provided asshown in FIG. 15, the effect of an interrupting surface 7 becomes morepositive.

As described above, in the present invention, the efficiency of coolingthe component parts within the disk device can be enhanced withoutincreasing an air flow loss (a power consumption), and the intrusion ofdust into the disk housing portion can be prevented.

Many different embodiments of the present invention may be constructedwithout departing from the spirit and scope of the invention. It shouldbe understood that the present invention is not limited to the specificembodiments described in this specification. To the contrary, thepresent invention is intended to cover various modifications andequivalent arrangements included within the spirit and scope of theclaims.

What is claimed is:
 1. A rotating disk storage device, comprising:acasing; a partition wall dividing an interior of said casing into a diskhousing chamber and a drive chamber; a recording disk disposed in saiddisk housing chamber; means for rotating said disk; an arm supporting aread/write head, said arm being adapted to extend into said disk housingchamber through an opening of said partition wall; means disposed insaid drive chamber for linearly moving said arm to cause said head toskim across a recording surface of said disk, said opening dividing saidpartition wall into upstream and downstream wall portions, said upstreamand downstream wall portions each having a front surface facing saiddisk in said disk chamber which is curved to generally conform to theouter peripheral curvature of said disk, said upstream wall portionending at said opening at a first edge area of said front surface whichis adjacent to said opening and spaced a first radial distance from theouter peripheral curvature of said disk, said downstream wall portionbeginning at a second edge area adjacent to a downstream edge of saidopening, said second edge area being spaced a second radial distancefrom the outer peripheral curvature of said disk which is less than saidfirst distance; and interrupting means, including a member which extendsfrom said downstream edge of said opening of said partition wall in adirection toward said drive chamber, for interrupting an air flow toconvert a dynamic pressure of said air flow into a static pressureadjacent said surface.
 2. A storage device according to claim 1, whereinsaid upstream wall portion of said partition wall directs the air flowtoward said interrupting means.
 3. A storage device according to claim2, wherein said upstream portion of said partition wall includes furtherportions which are diffused in a radial direction relative to therecording disk and disposed at opposite end portions of said partitionwall in the same direction of a rotating axis of the recording disk,respectively, said diffused portions being spread radially outwardly. 4.A storage device according to claim 2, wherein said upstream portion ofsaid portion wall is diffused in a radial direction relative to therecording disk and extends from one end portion of said partition wallto the other axial end portion thereof in the same direction of arotating axis of the recording disk, said diffused portion beingoutwardly diffused in a radial direction relative to the recording disk.5. A storage device according to claim 1, further comprising means forshifting said air flow outwardly in a radial direction relative to therecording disk.
 6. A storage device according to claim 5, wherein saidshifting means includes spoilers extending inwardly into said diskhousing chamber from said interrupting means in a radial directionrelative to said disk, said spoilers being respectively disposed atopposite end portions of said partition wall in the same direction of arotating axis of said disk.
 7. A storage device according to claim 6,wherein said shifting means includes an additional spoiler interposedbetween said spoilers in the same direction of the rotating axis of thesaid disk.
 8. A storage device according to claim 2, further comprisingmeans for shifting said air flow outwardly in the radial directionrelative to the said disk.
 9. A storage device according to claim 4,wherein said upstream of said partition wall portion is diffused to alarger degree at the axial opposite end portions of said partition wallthan at a portion of said partition wall between said axial opposite endportions.
 10. A storage device according to claim 2, wherein a radialgap between the outer peripheral curvature of said disk and an innerperipheral curvature of the upstream portion of said partition wall issmaller than that between said arm and the upstream portion of saidpartition wall.
 11. A storage device according to claim 2, wherein saidair flow passes along a passage defined between a tangential plane ofsaid partition wall and a plane passing through opening of saidpartition wall and being parallel to said tangential plane.
 12. Astorage device according to claim 1, wherein said interrupting meansincludes a plane extending parallel to said arm.
 13. A storage deviceaccording to claim 1, wherein said arm is reciprocally movable throughthe opening formed in said partition wall, and wherein an area of aportion of said opening located at an upstream side of said arm withrespect to said air flow is smaller than an area of a portion of saidopening located at the downstream side of said arm.
 14. A storage deviceaccording to claim 1, wherein said interrupting means is integral withsaid partition wall.
 15. A storage device according to claim 1, whereinsaid interrupting means is separate from said partition wall.